Marks placed on a letter to indicate pronunciation, stress or intonation, or to indicate a different meaning or different grammatical usage for the word within which they appear. For example, résumé, piñata, ou/où.

A word class that may modify or qualify a verb, an adjective or another adverb. For example, beautifully in she sings beautifully; really in he is really interesting; very and slowly in she walks very slowly.